1. School of Information Engineering, Robot Technology Used for Special Environment Key Laboratory of Sichuan Province, Southwest University of Science and Technology, Mianyang, China
2. School of Electronics and Information Engineering, Sichuan University, Chengdu, China
3. Department of Electronics, University of York, York, U.K.
4. CETUC, PUC-Rio, Rio de Janeiro, Brazil
5. Institute of Artificial Intelligence and Robotics, Xi’an Jiaotong University, Xi’an, Shaanxi Province, China